It is a gen - boxes papers certificates etc from an AD. I've had it now for a few years. This is part of the 'Blue' series of UN Maxi Marine chronographs. It started with the Blue Max and continued with this one - the Blue Wave, which was part of a limited edition of 1846 and is no longer made and was sold out at the AD's in 2006 (Now cannot be seen in the current catalogue - only in the Archived section online). The other watch shown by Fidestro/Snowball is one in the MMC series that came later - Blue Surf.
The current Blue watch is the Blue Seal as mentioned by JoeyDee.
I got mine in Switzerland and bought the watch with standard blue rubber strap with ti fittings and the stainless steel bracelet as a kind of impulse purchase while on biking holiday in the Swiss Alps. I was window shopping one evening - it caught my eye, and ...well you know how it is. I had a couple of gen rolex (Sub and Explorer) at the time and was blown away by the detail,colour, quality of finish and elegance of UN's non Dive-bezel design.
Since then I have tried to reduce the cost of my serial obsessions by becoming interested in reps.
I meant that RobbieG's photography was the inspiration for me to try to take and post some decent pictures. I recognise that I've some way to go but the details he posted of how to do it did help. Thanks for all the comments